Criteria for diagnosis in dermatology and dermatopathology: a critical evaluation

The logical processes of application of criteria to make diagnoses in dermatology and dermatopathology are examined. The limitations of use of a single criterion are delineated, and the advantages and limitations of multiple criteria are defined. It is important that all diagnostic criteria be applied with careful attention to the frequency of the designated entity in the study population and the sensitivities and specificities of the criteria used. The exclusive use of single, "favorite" criteria should be avoided, and multiple criteria should be applied, whenever possible.